How is freezing point depression used in real life?
Have you ever seen trucks sprinkling salt on icy roads in North America? Why should they do this?
You can also pour a bit of ethylene glycol into your radiator fluid. Clearly both practices arise from the severity of winters in North America, and the salty roads are also the reason you see so many rust-buckets on North American roads.
Of what else can I think? Here's a good one? How do you make ice cream at home? The stuff you make yourself with real cream, and fruit, and custard is much better than any ice cream you can buy. And typically you use an ice-salt mixture when you churn the ice cream.
In the laboratory, cryoscopy is sometimes used to estimate the molecular mass of a new substance, and this also relies on freezing point depression.